Giant river otter munching on a suckermouth catfish. These otters are the largest in the world, growing up to an average length of 5.5ft (1.7m) long and can weigh up to 70lbs (32kg). They belong to the mustelidae family of predators, which include weasels, badgers, ferrets, martens, minks and wolverines. Being as large as they are, they need to eat a lot of food to top up the tank. Each one of these absolute units requires 6 - 9lbs (2.7 - 4kg) of flesh per day.
They prefer fish, but they've also been known to eat the odd snake/miscellaneous river creature now and then. They are only found in South America, mainly in and around the Amazon river and the smaller rivers connected to it. They are considered apex predators because they aren't preyed upon by anything regularly. Thats not to say they aren't preyed on by anything ever. You know this to be true: eventually, everything in the wild gets eaten by something. The term Apex Predator is often confused with "never gets fucked with" and that is simply not true. Black caiman, anaconda and jaguar might take a giant river otter once in a blue moon, and while these instances are very rare they do happen. It does not change the giant otter's apex distinction.